The display device now being used on electronic devices such as notebook computers, PDAs, digital cameras, mobile phones, and the like generally is coupled on the host body through a hinge. The display device may be unfolded when in use, and be folded on the host body when not in use to reduce the size to facilitate storing and carrying.
Angular adjustment of the display device, notebook computers, small desktop computers or other foot stands generally is accomplished through the pivotal hinge which can be extended and folded in a stepless fashion. After closed, the body has a switch to latch the screen from opening. The hinge also provides a coupling and anchoring movement to generate a torque to close the screen. With constant advances of technologies, the larger CRT display device has been gradually replaced by the smaller flat display device. For instance, the flat LCD device has become a standard feature of the notebook computers and many desktop computers. With the size of the display device becomes smaller and lighter, the hinge also is smaller. The friction resistance between the elements is smaller and cannot provide enough torque to meet the requirements. As a result, the display device cannot be opened and closed in a stepless fashion. During closing, the display device could drop and close abruptly, and the stepless adjustment function is impaired. The display device and the host body could be damaged.